Improvement in hot-air furnaces



4 Svhe-ets--Sheet` l.Y

' 1. lonnsnn'. Hut-Air Furnaces.

,Patented Dec. 8,1874.

4 4Sheets--She13- 1. Jonsson. Hut-Air Furnaces.

=`Patented Dec. 8,1874.

No.157,6"08. l

UNITED STATES PATENT OEETOE.

JONATHAN JOHNSON, OF LOWELL, MASSACHUSETTS.

IMPROVEMENT IN HOT-AIR ifuRNAc'a-:al

Specification forming part of Letters Patent N o. 157,608, datedDecember 8, 1874; application led September 28, 1874. v

To all whom it may concern:

Be it known that I, JONATHAN JOHNSON, of the city of Lowell, county ofMiddlesex and State of Massachusetts, have invented certain new anduseful Improvements in Heating- Furnaces 5 and I do hereby declare thatthe following is a clear, full, and exact description thereof. such aswill enable others skilled in the art to which it pertains to make anduse the same.

This invention relates to that class of furnaces commonly termed steamor water heat ers, in which the heat of the burning fuel is principallyapplied to the heating of water, which in its turn heats the air used inwarming apartments, either by passing the air directly through thefurnace in contact with the heated pipes and reservoirs, the air beingadmitted at the bottom and passing upward and around the furnace,between the inner and outer cases, becoming sufficiently heated forwarming purposes without coming in contact with any surface of metal soheated as to vitiatethe air, and cause danger to those who inhale itfrom the abstraction of a portion of its oxygen, thus giving a pleasant,healthy atmosphere, with sufficient warmth to the apartments into whichit may be conducted 5 or heat is imparted to the air of the rooms byradiators from the pipes and reservoirs as they are carried throughdifferent parts of the building.

The object of the invention is to improvev the above-named class ofheating-furnaces, so as to avoid the vexatious trouble caused by theburning out of water-pipes and reservoirs, owin g to the dilcultyexperienced in keepin g up a uniform supply of water, thus causing anunsteady current through them, and, further, by the peculiarconstruct-ion of the fire-pot, preventing the deposit of clinkers uponits sides, which soon renders the furnace of ordinary constructionalmost useless; and it consists in the method of construction, as wellas the arrangement, of the various parts of the apparatus for heatingthe air and water, and controlling the circulation of the same, as willbe hereinafter set forth, and then pointed out in the claims.

In the accompanying drawings similar letters of reference indicatecorresponding parts in the different figures.

Figure l is a view, partly in perspective, showing the generalarrangement of the furnace, air and water pipes, and regulator, witliits connections. Fig. 2 is a vertical sectionof the furnace, showing thearrangement of the water-columns, annular reservoirs, and fuef bricklinings of the fire-pot. Fig. 3 presents a section ofthe regulatingdevice, showing the internal arrangement and its various connections.Fig. 4 is a horizontal section between `the fire-pot and supplementaryor dome heater. Fig. 5 is a horizontal section through the firepot.

By referring to the accompanying drawings, a base-plataA, will be seenresting upon appropriate supports, and provided with channels orprojecting anges for the purpose of retaining in position the outer caseB and inner case O, the latter forming the sides of the ash-pit, andsustaining the annular hollow reservoir, D, which is connected, by the`pipe E, with the regulator through which water is supplied to thefurnace. This reservoir D is connected, by a series of hollow col-4 umnsorpipes, F, with the annular reservoir G, which is formed in asimilarmanner to the lower one, D, but is placed in a reverse position,so that its inclined surface shall form no lodging-place for the coalwhen the fire-pot is to be replenished with fuel. Between these columnsor pipes F are placed the fire-bricks H, having an elongated rectangularshape, of nearly the same form and size as the space they are to occupy,but leaving sufficient room between them and the columns for the passageof the llame and heat, so that all portions of the surface of thecolumns shall be exposed thereto. A grate, I, is placed within the annular base D, and operated in any of the various ways known in the art.This arrangement forms a fire-pot possessing many advantages, it beingfound by experience that the intermixing of the water-tubes with thelirebrick keeps the temperature of its sides so low as to prevent theadhesion of clinkers, and at the same time prevent the deadening effectof a water-jacket wholly surrounding the iirepot upon the fuel, causingan imperfect combustion of that portion of the fuel :adjoining thejacket, with its accompanying evils, such as the escape of unburnedgases, ineffective heating-surface, and the continual care reqnis siteto keep the fire from going out. On the same plane as the upper surfaceof the annular reservoir G is a perforated plate, A, which forms thebase, upon which is raised the superstructure, consisting of the outerease B and inner case C', the whole being covered by the plate K, thusforming a dome-heater, and containing the series of water-columns I1",connecting the two annular reservoirs, D and G', the lower one of whichis connected with the res ervoir G by the pipes L, any desired number ofwhich may be used, soV arranged as not to interfere with the opening forthe introduction of fuel. This forms lan additional heatingchamber, fromwhich the heated water and steam pass through the pipe Sto the differentreservoirs or coils of pipe from which the heat is radiated, and finallyreaches the regulator N. This regulator and supply-tank may be placed ata level above that of the furnace by the introduction of a commoncheck-valve, or at a level above the upper circulating-pipe without avalve, and is constructed as follows: A conical vessel, having suitablestands upon which it rests, and by means ot' which it may be secured inposition, is provided with a head, O, secured to the cylinder by awatertight joint, formed by a gasket of rubber or other suitablematerial inserted in the joint, and also having an inlet-pipe, P, comingfrom any suitable source of water-supply, attached to its small end, andentering its interior to a sufficient distance to allow of the insertionof a valve or cock, Q, to which is attached the iioatR. It will beevident that, should the water within the tank fall below a certainpredetermined line, the falling of the float will open the cock andadmit a supply from without 5 but this is only necessary so far as tosupply wastage, as the water passing out of the regulator through thepipe E, which enters it below the water-line after circulating throughthe furnace, is returned to it through the pipe S, this circulationbeing caused by the wellknown fact, that heat causes water to rise. It,being heated in passing through the furnace, rises through the pipe Sand its various connections, but, losing a portion of its caloricthrough radiators, descends through the regulator and pipe E to thefurnace again, thus completing the circuit. A waste-pipe, T, enters thetop of the regulator, and serves to Y carry off any surplus of water orsteam which may accumulate therein. A cock, V, is also inserted for thepurpose'of supplying at all times hot water for culinary or otherpurposes.

It will be observed that this arrangement allows no more water to enterthe circulation than is absolutely needed to keep up the supply, therebyutilizing, as far as possible, all the heat.

It will be seen when, in order to economize space, or for other reason,it becomes necessary to dispense-with the heating-dome and itsappendages, the pipe S may be connected with the annular reservoir G byremoving the plug V, and screwing the pipe into the oriice closed by it;and, in like manner, should it be desired to attach thewater-circulation to a furnace already in use, the dome-heater may beplaced in position, leaving the lire-pot of the furnace intact, theconnection of the inletpipe E being made by removing the plug V andputting the inlet-pipe in its place. When used in this way, the annularreservoir and pipes forming the heater may be supported by the rod W,provided with a spider at its lower end, upon which the reservoir Drests, and having a screw-nut at its upper end, by which it is suspendedfrom plate K, which rests upon the inner casing C.

A pipe for the exit of the smoke is shown at a, but may be differentlylocated, if desired. v

The base-plate A is perforated with a series of openings, similar tothose in the plate A, for the passage of the cold air entering thefurnace, which, as it is being heated, ascends through the annular spacebetween the outer and inner cases, and, finally, makes its exit throughthe opening b at its top.

The operation of the devices herein enumerated will be readilyunderstood from the description and drawings; but their greatsuperiority in service, caused by the simplicity and absence ofliability to deran gement ot' the various parts over other arrangementsfor a similar purpose, becomes fully apparent when the apparatus is putinto actual use.

Having thus described my invention, I claim as new, and desire to secureby Letters Patent, the following:

l. In a heating -furnaee, a lire-pot lining composed of alternatewater-columns and lirebricks, with spaces between for the passage offlame and smoke, substantially as herein described.

2. The combination, in aheating-furnace, of a dome-heater composed ofthe annular reservoirs D `Gr and the pipes F, the whole being suspendedwithin a metallic case surrounded by an inclosed air-chamber, as setforth.

3. In a heating-furnace, a fire-pot lining composed of alternatewater-columns and firebricks,in combination with an inner and outermetallic shell, having' an air-space between them, and a dome-heatercomposed of the annular reservoirs and connecting-pipes, as and for thepurpose specified.

In testimony that I claim the foregoing I hereunto set my hand this 18thday of September, 1874, in the presence of two wit- DCSSGS.

J. JOHNSON.

Witnesses:

ANDREW F. J nwn'r'r, JOHN P. VARNUM.

